Model glassy inhomogeneous polymer networks

Summary A new procedure for the preparation of model polymer networks having an inhomogeneous distribution of crosslinks has been developed. Emulsion polymerized polystyrene/divinylbenzene microspheres, of uniform particle size, are swollen with styréne monomer, which is later polymerized in situ. The resulting network consists of discrete sites of crosslinked material dispersed in an interpenetrating matrix, and is suggested as a model for the nodular morphology which has been observed in some epoxy networks. The results of initial studies showing the effects of nodule size and concentration on the fracture toughness of the glassy networks are presented.